#!/bin/bash

while true
do
    clear
    echo "====================="
    echo "        MENU         "
    echo "====================="
    echo "1. Show disk usage"
    echo "2. Show system uptime"
    echo "3. Show the users logged into the system"
    echo "4. Exit"
    echo ""
    read -p "Enter your choice [1-4]: " choice

    case $choice in
        1)
            df -h
            read -p "Press [Enter] key to continue..." readEnterKey
            ;;
        2)
            uptime
            read -p "Press [Enter] key to continue..." readEnterKey
            ;;
        3)
            who
            read -p "Press [Enter] key to continue..." readEnterKey
            ;;
        4)
            exit 0
            ;;
        *)
            echo "Error: Invalid option..."
            read -p "Press [Enter] key to continue..." readEnterKey
            ;;
    esac
done
